Experimental observation of time singularity in classical-to-quantum chaos transition

TL;DR

This paper reports the first experimental observation of a time singularity indicating a transition from classical to quantum chaos, highlighting a sudden change in system memory behaviors and drawing parallels to dynamical quantum phase transitions.

Contribution

It provides the first experimental evidence of a time singularity in chaotic systems, revealing a new physical origin distinct from regular systems.

Findings

Observation of time singularity in chaotic quantum systems

Identification of a sudden change in system memory behaviors

Connection to dynamical quantum phase transition concepts

Abstract

The emergence of chaotic phenomena in a quantum system has long been an elusive subject. Experimental progresses in this subject have become urgently needed in recent years, when considerable theoretical studies have unveiled the vital roles of chaos in a broad range of topics in quantum physics. Here, we report the first experimental observation of time singularity, that signals a classical-to-quantum chaos transition and finds its origin in the {\it sudden change} in system's memory behaviors. The time singularity observed is an analog of the "dynamical quantum phase transition" (DQPT) -- proposed very recently for regular systems -- in chaotic systems, but with totally different physical origin.